CVE-2021-26427

—

CVSS 3.1

9.0 critical

EPSS

<1%p57

Published

Oct 13, 2021 (Oct 13, 2021)

Modified

Jun 17, 2026

Description

Microsoft Exchange Server Remote Code Execution Vulnerability

Vendors: microsoft
Products: exchange server
Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

NVD CVE.org GitHub PoCs EPSS (0.9%)

In the news4 stories

Patch Tuesday, October 2021 Edition

Krebs on SecurityOct 15, 00:00 UTC · Oct 15, 2021Vulnerability CVE-2021-30883 CVE-2021-38672 CVE-2021-40461+3 CVEs1

60

Update Your Windows PCs Immediately to Patch New 0

The Hacker NewsOct 15, 00:00 UTC · Oct 15, 2021Vulnerability in the wildCVE-2021-40449 CVE-2021-41335 CVE-2021-40469+10 CVEs

60

Microsoft Patch Tuesday for Oct. 2021 — Snort rules and prominent vulnerabilities

Cisco TalosOct 12, 17:33 UTC · Oct 12, 2021Vulnerability in the wildCVE-2021-40461 CVE-2021-38672 CVE-2021-40449+6 CVEs

60

Microsoft patches actively exploited Windows zero-day (CVE-2021-40449)

Help Net SecurityOct 12, 00:00 UTC · Oct 12, 2021Exploit / PoC in the wildCVE-2021-40449 CVE-2021-40486 CVE-2021-26427+5 CVEs

60